code: def validate_environment(api_key):
      headers = {
          "accept": "application/json",
          "content-type": "application/json",
      }
      if api_key:
          headers["Authorization"] = f"Bearer {api_key}"
      return headers
  
file_path: litellm/litellm/llms/cohere.py
imports: import os, types
  import json
  from enum import Enum
  import requests
  import time, traceback
  from typing import Callable, Optional
  from litellm.utils import ModelResponse, Choices, Message, Usage
  import litellm
  import httpx
label_desc: Use image node_id 1 for calling a global function with example usage: validate_environment(api_key) and returns: headers